Sprint Filter P08 Air Filter for Road & Track – BMW R 1200 GS Rally (2012–2018) PM109S

Ride alone and a boxer meets the air of the road it is on. Ride third in a line of four on a dry gravel section and it meets the air of the two machines in front, which is a different substance: lifted, suspended, still hanging at head height long after the wheel that raised it has gone. The R 1200 GS Rally is bought to be ridden in company on exactly that surface, and the question when choosing its element is not how hard it is ridden but where in the line it usually sits.

Key Features

• One woven layer of polyester, supplied dry and kept dry: no oil when new, none after a wash
• P08 specification: an 80 µm aperture rated at 5,050 l/m²/sec, the medium for road and track
• Polyester threads from ø 22 microns across; the gaps between them do the filtering
• Roughly twice the filtering cloth of a typical performance element
• Seats in the series airbox where the paper panel came out: nothing trimmed, no remap
• Cleaned and refitted rather than discarded, specified for the life of the machine

Your air is chosen by the rider in front

Dust behaves unhelpfully in a group. The coarse part thrown up by a front tyre falls back within a second or two; the fine part rises and stays, and a machine following at a sensible distance rides through it for the whole section. The lead bike is on clean air, the second is in a thin haze, everything behind that is breathing the road twice. None of this depends on speed or on how the throttle is used — it depends on the running order, which is why two identical machines leaving the same car park can come back with airboxes in visibly different condition.

Where the standard weave belongs

For most owners this is the right element: most of an adventure bike's year is tarmac, and the P08 gives away nothing there — 5,050 l/m²/sec through an 80 µm weave, with 93.13 per cent retention of 100-micron test particles in Sprint Filter's own comparison, against 76.42 per cent for four-layer oiled cotton. What it will not do is add power: no element inside an unmodified airbox does. Riders who spend whole days at the back of a group on loose ground should read the PM109T12 listing instead: the same housing takes a far finer non-woven and gives up flow to get it.

Care and cleaning

PM109S is serviced with an air line held to its clean face and blown outward, so the load leaves by the route it arrived. If a season of gravel roads leaves a film that air will not lift, hand-warm water and mild detergent will, rinsed until clear. Then moving air and nothing warmer — no heat gun, no radiator, no flame, since heat is what ends a polyester element — and refit it dry. The maintenance sheet is filed under the Downloads tab.

Fitment & Compatibility

Listed for the BMW R 1200 GS Rally of 2012 to 2018, in the series airbox. Fifteen machines share the part number: the HP2 models, the R 1200 S, ST, R and RT, the GS and its Adventure, and the whole R nineT family. The much shorter list of the 7-micron PM109T12 is drawn only from the GS and HP2 side of that group. Every entry appears with its model years in the Fitment tab.